1. Field of the Present Disclosure
The present disclosure relates to an image processing apparatus.
2. Description of the Related Art
An image processing apparatus finds character blocks in an image, determines respective representative colors of the character blocks, unifies plural character blocks between which the representative color difference and the distance are small, and consequently reduces a file size of a highly compressed PDF (Portable Document Format).
However, the aforementioned technique unifies only character blocks between which the representative color difference and the distance are small, and consequently leaves a lot of character blocks (i.e. a lot of character colors). A highly compressed PDF is obtained by independently compressing respective character planes of which the number is the same as the number of the aforementioned character blocks. Therefore, the aforementioned technique does not result in a small file size of the highly compressed PDF. In addition, if a black character or a white character is unified, a black character or a white character is changed to a gray character, and consequently the spoiled image quality is easily perceived.